Off-track ski boots differ from ski boots by the fact that they must alternatively permit the skier both to ski and to walk as easily as possible.
To permit the two configurations, respectively walking and skiing, they envisage that the leg portion of the boot, that is the upper part which embraces the lower end of the skier's leg, can rotate in relation to the foot portion, that is, the lower part of the boot which embraces the foot. In particular, the rotation of the leg portion in relation to the foot portion, moves along with and facilitates walking. Such relative rotation may be blocked, by making the leg portion integral with the foot portion, to permit skiing.
The passage from one configuration to the other needs to be as fast and easy a possible given that when practising off-track skiing the skier needs to change the configuration of the boot very frequently depending on the section of path to be tackled each time.
The solutions of the prior art envisage hinging of the leg portion to the foot portion, and guiding of the rotation movement by at least one rod.
At a first fixed end the rod is hinged to the foot portion while at a second, free end, it slides inside a guide attached to the leg portion.
In the walking position, the free end of the rod may slide inside the guide attached to the leg portion while, in the skiing position, the free end of the rod is made integral with the guide and thereby with the leg portion.
Such closure or blockage of the rod may take place by operating a peg which engages in a hole on the rod specially made for it.
As of today the solutions of the prior art have been unable to assure the skier an easy walk.
In fact, while on the one hand the blocking mechanism of the prior art is efficient for the skiing position, on the other the waking configuration is not very easy. In other words, the rod tends to stick inside the guide de facto making walking particularly tiring. The problem is further accentuated by the low operating temperatures and the snow/ice which, during use, tend to further penetrate between the rod and the relative guide, making the sliding thereof increasingly difficult.
Moreover, the type of guide of the leg portion used by the prior solutions poses strong limitations on the reciprocal positions of the connection hinges of the leg portion to the foot portion and the anchorages of the guide rod. These geometric limitations only partially limit the problem of sticking of the leg portion but, on the other hand, create enormous limitations to the overall appearance and functionality of the boot.